Something is odd

[WarpathEngineering]

I pulled my truck out of it's winter storage yesterday evening and took it for a drive in preparation of taking it to the body shop to get the rear quarter repaired from the jack*ss that backed into me last fall. I had put it away with 2 full tanks of fresh gas w/ Sta-bil and started it up a couple of times over the winter. With several of pumps of the pedal and a fair amount of cranking it started up and I helped it a little bit before it would idle on it's own and then off I went.

I'd say I was 3 or 4 miles from the house and all of a sudden it started to run like crap, spitting and sputtering. I pulled up to a red light with the idea of turning around and heading back home. I looked in the mirror and saw the exhaust pushing out black smoke, idle was rough and down below 500 rpm. I switched tanks. When the light changed I got it into a corner gas stations and left it run while I climbed under the hood. Everything appeared to be where it should have been so I removed the air cleaner lid. The engine seemed to take a gulp of air and calm down a little. The filter was clean, the choke was fully open as was the damper on the cleaner assembly. Not finding anything obvious, I put the lid back on and drove home.

It ran better on the way home but not great and while I had gotten my idle back I noticed a puff of black smoke as I backed it into the drive. Being a new to me truck, I started last spring with new cap, rotor, coil, wires, plugs, oil & filter change, new vacuum hoses & swapped my old carb with one from Guaranteed Carburetor. What I failed to do was do a compression test, check the timing & set the carb which is now on the schedule for tomorrow. Other than that anyone have any suggestions on where to look?